Success!
There was one detail that was keeping the DB converter from properly reading the old DB99b files correctly. It couldn't read them because of the way that I backed them up. What I did was burn that old ICQ directory (DB99b) onto a CDR, along with other files I needed to back up. Apparently when you burn files onto a CDR, the attributes are changed to "read only" under the properties of the file(s). This is what kept the DB converter from properly modifying these files.
This time, I did the same thing, only one thing different: I installed ICQ2000a, registered my existing #, then I closed ICQ. I copied the DB99b directory off the CDR to my desktop. Same as before.
Then this is what I did different: I then went into the DB99b, desktop directory and selected all the files in there. I right clicked, and chose properties, and unchecked the "read only" attribute.
After that, I followed the what I did in the past, I copied all of these old files, into the new Program Files/ICQ/2000a directory, and selected yes when prompted to overwrite all files. I then ran the DB, and viola, ICQ2000a opened up and all my contacts were there. Actually, two different numbers where restored, with no problems. I don't know if this is the trouble other people have been having but hopefully this will work for you.
Btw, thx for all the responces everyone.